Modern vehicles include various electronic control units, such as microprocessors and controllers, that are programmed to control vehicle operations. Such control units include, for example, an Electronic Control Module (ECM) or on-board computer. The control units are designed to monitor the operation of vehicle electronics so as to optimize vehicle performance. For example, control units such as an ECM can monitor the amount of carbon monoxide in the engine exhaust and adjust the fuel/air ratio entering the cylinders in order to optimize combustion efficiency.
When multiple control units are available, they are typically interconnected so that certain key data is globally available. The data can be accessed by a user through an information port. Diagnostic systems are commonly used to obtain (and sometimes transmit) data through the information port. Accordingly, the diagnostic system can be used to monitor and adjust the operation of various systems of the vehicle, and also detect malfunctions.
Traditional diagnostic systems are provided in the form of units that are coupled to the information port by means of a data cable. The large diagnostic systems typically include a computer, a monitor, and a keyboard. Smaller, portable diagnostic systems are also now available. For example, U.S. Pat. No. 6,693,367, which is assigned to the assignee of the present application, shows a portable, hand-held vehicle diagnostic display unit that is configured such that a user can simultaneously lift and operate the diagnostic display unit with a single hand.
The portable, hand-held vehicle diagnostic display unit disclosed in U.S. Pat. No. 6,693,367 includes a display screen contained within a housing of the unit. The display screen is viewable through a window of a front panel of the housing and is protected by a layer of transparent plastic, such as a 0.1 inch layer of Lexan® resin polycarbonate. When the layer of transparent plastic becomes scratched or damaged such that the display screen is not viewable as desired, then the display unit is returned to the manufacturer for replacement of the layer of transparent plastic. During replacement, the manufacturer disassemblies the front panel of the housing, removes the used layer of transparent plastic, inserts a new layer of transparent plastic over the display screen, and reassemblies the front panel to the unit. Alternatively, the layer of transparent plastic may be provided as a part of the front panel, such that the entire front panel is replaced.
What is still desired is a new and improved automotive diagnostic display unit. Preferably, the automotive diagnostic display unit will be portable and configured such that a user can simultaneously lift and operate the diagnostic display unit with a single hand. The new and improved automotive diagnostic display unit will also preferably be provided with a user-replaceable, transparent protective cover for the display screen.